docs: async def mail(
          self,
          sender: str,
          options: Iterable[str] = None,
          timeout: DefaultNumType = _default,
      ) -> SMTPResponse:
          """
          Send an SMTP MAIL command, which specifies the message sender and
          begins a new mail transfer session ("envelope").
  
          :raises SMTPSenderRefused: on unexpected server response code
          """
          await self._ehlo_or_helo_if_needed()
  
          if options is None:
              options = []
  
          options_bytes = [option.encode("ascii") for option in options]
          from_string = b"FROM:" + quote_address(sender).encode("ascii")
  
          async with self._command_lock:
              response = await self.execute_command(
                  b"MAIL", from_string, *options_bytes, timeout=timeout
              )
  
          if response.code != SMTPStatus.completed:
              raise SMTPSenderRefused(response.code, response.message, sender)
  
          return response